Patent GB-882204-A (GB)
Title: Discontinuously operating mixing and masticating apparatus for rubber and plastic compositions
IPC: B29B7/26
Filed: 1958-03-20
Abstract: 882,204. Batch-mixing apparatus. KRAUSSMAFFEI A.G. March 20, 1958 [March 22, 1957], No. 8957/58. Class 86. A batch-mixing and masticating apparatus for rubber and plastic compositions, comprises a mixing chamber 1 Fig. 1; a pair of rotors 2 arranged horizontally side by side in the chamber; a pressure ram 43 slidable in a vertical filling tube 34 connected to the top of the chamber 1; and a cover 5 for a discharge outlet of the chamber, wherein the cover, when closed, is disposed normal to the driving shafts 6 of the rotors passing on fluid-tight runners through the case wall of the chamber, the inlet tube is of circular cross-section and the rotors convey the mixture towards the outlet, whereby the apparatus is self-cleaning. The rotors 2 have hubs of detachably slidable on the ends of the shafts 6 which pass through seals in the case wall 3 of the chamber 1 as described with reference to Fig. 8, (not shown). The shafts 6 are rotatable in bearings 9 carried by a frame 11 and gear wheels 29 on the shafts engage with gear wheels 30 on a driving shaft 32 disposed below and between the shafts 6. Heating or cooling medium is supplied to the interiors of the rotors 2 by tubes 21 having nozzles 28 and passing through cavities 22 in the shafts 6 the medium being discharged through the cavities. Each tube and cavity open into separate chambers of a supply gland 26. The cross-sectional shapes of the mixing chamber and the rotors are as shown in Fig. 5, and the ends of the major axes of the elliptical cross-sections of each rotor are arranged to lie on helical lines whereby the rotating rotor imparts a thrust to the material in the discharge direction. The cover 5 is hinged at 4 to the apparatus frame and is pivoted to a cross-bar 53 Fig. 2, which is pivoted at its ends to brackets 55 carried by bushes 56 slidable on vertical columns 57. The upper ends 58 Fig. 1, of the columns 57 are pivotal to a limited extent on the apparatus frame whilst the lower ends of the columns terminate in hydraulic cylinders 59 of which the horizontal pistons 60 are connected at 61 to the apparatus frame, whereby the cylinders 59 and the cover 5 connected thereto are drawn tightly against the discharge opening of the mixing chamber. Each cylinder 59 carries a vertical hydraulic cylinder 62 of which the piston 65 is connected to a rod 63 in turn secured through a member 64 to one of the bushes 56, whereby the bushes and the cross-bar may be moved vertically relative to the columns 57 so that the cover rotates about the hinge 4 to a horizontal open position. The cover has annular passages 51 for heating or cooling medium passing through tubes 52. Heating and cooling passages 48 are also provided in the wall of the inlet tube 34 and the shell 33 of the mixing chamber 1. The ram 43 has a cavity 49 supplied with heating or cooling medium through a tube 50. The piston rod 44 of the ram is connected to a yoke 45 Fig. 2, connected at its ends to connecting rods 46 of pistons in pneumatic cylinders 47. Material is fed into the inlet tube 34 through a shoot having sector-shaped sides 36 with a hinged bottom 38 which is swingable by a pneumatic cylinder 39 into the position shown in Fig. 1, whereby it forms part of the wall of the tube 34 and serves as a guide for the ram. The gap between the cover 5, when closed, and the end faces of the rotors is maintained free of mixture by means of discs fixed to the cover and corporating with discs on the end faces of the rotors, as described with reference to Figs. 6 and 7 (not shown).